Research on Thermal Stress Analysis of Glass-Based Deep Trench Capacitor

With the rapid development of 2.5D/3D packaging technologies, glass substrates have emerged as a core technology in advanced packaging. However, as chip performance and interconnection density continue to increase, electromagnetic interference (EMI) and power integrity issues induced by high frequency signals and high power density in glass-based packaging are becoming increasingly critical. Deep trench capacitor (DTC) embedded in glass substrate through TGV technology not only effectively suppress EMI and optimize power distribution network, but also provide compact capacitive solutions for high-density interconnection. Nevertheless, thermal stress analysis during the manufacturing process of DTC, particularly reliability challenges caused by reflow soldering, remains insufficiently explored. This paper investigates the thermal stress distribution and its effects in glass-based DTC during reflow process. Finite element simulations are conducted to systematically analyze the thermal stress behavior. It is found that the maximum deformation and the maximum stress occur at the top of the substrate and the corner of the trench, respectively. In addition, this paper examines how different substrate materials and trench geometry (depth and pitch) affect thermal stress.